Added Test Code
Improved CommandList

[!] Fixed NullPointerException checking when using getCmd()
[+] Added listCmds() method to automatically create an array and get
commands from int A to int B
Improved Command

[=] isEmpty() is now private (never needed to be public)
[+] Added a getArg() to get a argument directly
[!] Improved combineArgs() to make it so you can combine args from int A
to int B (usefull when you already used the first few arguments).